Summary:
When placing a painting, it checks for intersections with other paintings and most blocks, but does not check for intersections with glow item frames. As a result, they can overlap, which causes heavy z-fighting.

Normal item frames used to have the same issue: MCPE-80079

Steps to Reproduce:

1. Build a wall
2. Place a glow item frame on the wall
3. Place a painting to the left of it

Observed Results:
The painting and glow item frame overlap.

Expected Results:
The painting treats the glow item frame the same as another 1x1 painting, and will choose a size such that the occupied block is not overlapped.

Screenshot: